diff options
Diffstat (limited to 'drivers/mtd/nand/onenand/onenand_bbt.c')
| -rw-r--r-- | drivers/mtd/nand/onenand/onenand_bbt.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/mtd/nand/onenand/onenand_bbt.c b/drivers/mtd/nand/onenand/onenand_bbt.c new file mode 100644 index 0000000..dde2048 --- /dev/null +++ b/drivers/mtd/nand/onenand/onenand_bbt.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Bad Block Table support for the OneNAND driver + * + * Copyright(c) 2005 Samsung Electronics + * Kyungmin Park <kyungmin.park@samsung.com> + * + * Derived from nand_bbt.c + * + * TODO: + * Split BBT core and chip specific BBT. + */ + +#include <linux/slab.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/onenand.h> +#include <linux/export.h> + +/** + * check_short_pattern - [GENERIC] check if a pattern is in the buffer + * @param buf the buffer to search + * @param len the length of buffer to search + * @param paglen the pagelength + * @param td search pattern descriptor + * + * Check for a pattern at the given place. Used to search bad block + * tables and good / bad block identifiers. Same as check_pattern, but + * no optional empty check and the pattern is expected to start + * at offset 0. + * + */ +static int check_short_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td) +{ + int i; + uint8_t *p = buf; + + /* Compare the pattern */ + for (i = 0; i < td->len; i++) { + if (p[i] != td->pattern[i]) + return -1; + } + return 0; +} + +/** + * create_bbt - [GENERIC] Create a bad block table by scanning the device + * @param mtd MTD device structure + * @param buf temporary buffer + * @param bd descriptor for the good/bad block search pattern + * @param chip create the table for a specific chip, -1 read all chips. + * Applies only if NAND_BBT_PERCHIP option is set + * + * Create a bad block table by scanning the device + * for the given good/bad block identify pattern + */ +static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip) +{ + struct onenand_chip *this = mtd->priv; + struct bbm_info *bbm = this->bbm; + int i, j, numblocks, len, scanlen; + int startblock; + loff_t from; + size_t readlen, ooblen; + struct mtd_oob_ops ops; + int rgn; + + printk(KERN_INFO "Scanning device for bad blocks\n"); + + len = 2; + + /* We need only read few bytes from the OOB area */ + scanlen = ooblen = 0; + readlen = bd->len; + + /* chip == -1 case only */ + /* Note that numblocks is 2 * (real numblocks) here; + * see i += 2 below as it makses shifting and masking less painful + */ + numblocks = this->chipsize >> (bbm->bbt_erase_shift - 1); + startblock = 0; + from = 0; + + ops.mode = MTD_OPS_PLACE_OOB; + ops.ooblen = readlen; + ops.oobbuf = buf; + ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0; + + for (i = startblock; i < numblocks; ) { + int ret; + + for (j = 0; j < len; j++) { + /* No need to read pages fully, + * just read required OOB bytes */ + ret = onenand_bbt_read_oob(mtd, + from + j * this->writesize + bd->offs, &ops); + + /* If it is a initial bad block, just ignore it */ + if (ret == ONENAND_BBT_READ_FATAL_ERROR) + return -EIO; + + if (ret || check_short_pattern(&buf[j * scanlen], + scanlen, this->writesize, bd)) { + bbm->bbt[i >> 3] |= 0x03 << (i & 0x6); + printk(KERN_INFO "OneNAND eraseblock %d is an " + "initial bad block\n", i >> 1); + mtd->ecc_stats.badblocks++; + break; + } + } + i += 2; + + if (FLEXONENAND(this)) { + rgn = flexonenand_region(mtd, from); + from += mtd->eraseregions[rgn].erasesize; + } else + from += (1 << bbm->bbt_erase_shift); + } + + return 0; +} + + +/** + * onenand_memory_bbt - [GENERIC] create a memory based bad block table + * @param mtd MTD device structure + * @param bd descriptor for the good/bad block search pattern + * + * The function creates a memory based bbt by scanning the device + * for manufacturer / software marked good / bad blocks + */ +static inline int onenand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd) +{ + struct onenand_chip *this = mtd->priv; + + return create_bbt(mtd, this->page_buf, bd, -1); +} + +/** + * onenand_isbad_bbt - [OneNAND Interface] Check if a block is bad + * @param mtd MTD device structure + * @param offs offset in the device + * @param allowbbt allow access to bad block table region + */ +static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) +{ + struct onenand_chip *this = mtd->priv; + struct bbm_info *bbm = this->bbm; + int block; + uint8_t res; + + /* Get block number * 2 */ + block = (int) (onenand_block(this, offs) << 1); + res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03; + + pr_debug("onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n", + (unsigned int) offs, block >> 1, res); + + switch ((int) res) { + case 0x00: return 0; + case 0x01: return 1; + case 0x02: return allowbbt ? 0 : 1; + } + + return 1; +} + +/** + * onenand_scan_bbt - [OneNAND Interface] scan, find, read and maybe create bad block table(s) + * @param mtd MTD device structure + * @param bd descriptor for the good/bad block search pattern + * + * The function checks, if a bad block table(s) is/are already + * available. If not it scans the device for manufacturer + * marked good / bad blocks and writes the bad block table(s) to + * the selected place. + * + * The bad block table memory is allocated here. It is freed + * by the onenand_release function. + * + */ +static int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) +{ + struct onenand_chip *this = mtd->priv; + struct bbm_info *bbm = this->bbm; + int len, ret = 0; + + len = this->chipsize >> (this->erase_shift + 2); + /* Allocate memory (2bit per block) and clear the memory bad block table */ + bbm->bbt = kzalloc(len, GFP_KERNEL); + if (!bbm->bbt) + return -ENOMEM; + + /* Set the bad block position */ + bbm->badblockpos = ONENAND_BADBLOCK_POS; + + /* Set erase shift */ + bbm->bbt_erase_shift = this->erase_shift; + + if (!bbm->isbad_bbt) + bbm->isbad_bbt = onenand_isbad_bbt; + + /* Scan the device to build a memory based bad block table */ + if ((ret = onenand_memory_bbt(mtd, bd))) { + printk(KERN_ERR "onenand_scan_bbt: Can't scan flash and build the RAM-based BBT\n"); + kfree(bbm->bbt); + bbm->bbt = NULL; + } + + return ret; +} + +/* + * Define some generic bad / good block scan pattern which are used + * while scanning a device for factory marked good / bad blocks. + */ +static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; + +static struct nand_bbt_descr largepage_memorybased = { + .options = 0, + .offs = 0, + .len = 2, + .pattern = scan_ff_pattern, +}; + +/** + * onenand_default_bbt - [OneNAND Interface] Select a default bad block table for the device + * @param mtd MTD device structure + * + * This function selects the default bad block table + * support for the device and calls the onenand_scan_bbt function + */ +int onenand_default_bbt(struct mtd_info *mtd) +{ + struct onenand_chip *this = mtd->priv; + struct bbm_info *bbm; + + this->bbm = kzalloc(sizeof(struct bbm_info), GFP_KERNEL); + if (!this->bbm) + return -ENOMEM; + + bbm = this->bbm; + + /* 1KB page has same configuration as 2KB page */ + if (!bbm->badblock_pattern) + bbm->badblock_pattern = &largepage_memorybased; + + return onenand_scan_bbt(mtd, bbm->badblock_pattern); +} |
